* Resetting the PCM (Powertrain Control Module): This is the main computer controlling the engine, transmission, and other drivetrain components. A full PCM reset usually requires disconnecting the negative battery terminal for a period of time (at least 30 minutes, sometimes longer). This clears various stored data, including trouble codes (but not the underlying problem that caused them). Caution: Disconnecting the battery will erase radio presets and other personalized settings.
* Clearing Trouble Codes (Check Engine Light): This doesn't reset the PCM itself, but it clears the diagnostic trouble codes (DTCs) stored in the PCM's memory. You can do this with a dedicated OBD-II code reader and scanner. Many inexpensive ones are available online and at auto parts stores. The scanner will allow you to read the codes, clear them, and sometimes even provide possible causes. Clearing the codes doesn't fix the problem, only removes the warning light.
* Resetting the Electronic Throttle Control (ETC): If you're experiencing issues with throttle response, a specific ETC reset might be needed. The procedure varies by year and model, and you'll likely find instructions in your owner's manual or online forums specific to your Chrysler 300 Hemi year. This usually involves a specific key-turning sequence.
* Resetting other modules (e.g., radio, infotainment): These usually have their own reset procedures. Consult your owner's manual for specific instructions.
In short: To clear trouble codes or perform a general reset, disconnecting the battery's negative terminal for at least 30 minutes is the most common approach. However, for more specific issues, using an OBD-II scanner and researching your specific car year and model is recommended. Always refer to your owner's manual for the safest and most effective methods.
